An effort under way across industries and government to protect GPS signals from interference by other bandwidth users is now focused on the U.S. Congress.

The Coalition to Save Our GPS, of which AOPA is an active member, is urging members of the House and Senate to register their concerns with the Federal Communications Commission (FCC) about the risk of signal interference or degradation that GPS could face from mobile network operator LightSquared’s plan to expand into bandwidth adjacent to that used by GPS. LightSquared received a conditional waiver to proceed if testing—to be performed under the company’s supervision—reveals no threat to the much lower-powered GPS signals.

“Our industry cannot allow GPS to be threatened by interference and we appreciate Congress’ attention to this urgent matter,” said AOPA Vice President of Legislative Affairs Lorraine Howerton, who serves as the chair of the General Aviation Working Group on the coalition. She continued, “AOPA is proud to work with our industry stakeholders in an effort to educate members [of Congress] on the disruptive consequences that will arise from the FCC’s hasty and ill-advised waiver to LightSquared.”

On behalf of the aviation industry, AOPA and fellow coalition members ATA, EAA, GAMA, NATA, and NBAA have been working to rally more members of Congress to the cause of ensuring the integrity of GPS. “This is a matter of serious concern to the aviation industry and much of U.S. commerce, and we respectfully request that you require the FCC to take all steps necessary to protect the GPS,” the aviation coalition members wrote in the May 10 letters to the House and Senate.

“Thousands of aircraft use GPS receivers for navigation, including approach and landing and it is central to the Federal Aviation Administration’s ADS-B-based Next Generation Air Transportation System. GPS is used for the cellular telephone E-911 program and helps first responders locate people in emergencies,” the letters to the elected officials said. “We are extremely concerned that these receivers could be jammed within miles of LightSquared’s transmitters and the consequences of disruption to the GPS signals are far reaching, creating 40,000 ‘dead spots’ each miles in diameter through U.S. cities.”

The letters criticized the waiver granted LightSquared as “highly unusual” and deemed the proposed network expansion “fundamentally different from the ‘ancillary terrestrial component’ of satellite based services that the FCC’s rules permit and by every indication to date, is incompatible with existing GPS use.”